Railway traffic controlling apparatus



H. A THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed July 13, 1932 ma m @QQ QQ QQ W wbs g IN VENTO'R Howard A. Thompson BY a/z-Alma HIS ATTORNEY Patented Mar. 15, 1938 RAILWAY TRAFFIC CONTROLLING APPA- RATUS Howard A. Thompson, Edgewood, Pa., assignor to The Union Switch 8; Signal Company, Swissvalc, Pa., a corporation of Pennsylvania Original application July 13, 1932, Serial No.

622,257, now Patent No. 2,018,818, dated October 29, 1935. Divided and this application September 26, 1935, Serial No. 42,216

1 Claim.

My invention relates to railway traffic controlling apparatus, and particularly to control circuits for railway switch control systems. The present application is a division of my copend ing application filed July 13, 1932, Serial No. 622,257, for Railway traffic controlling apparatus, now United States Patent No. 2,018,818, issued October 29, 1935.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in the claim.

A feature of my invention is the provision of double wire control circuits for governing the operation of a railway track switch, and with which circuits an accidental connection of a control wire with the current source will be de tected either immediately or at the next operation of the apparatus. Other features and advantages of my invention will appear as the specification progresses.

For a better understanding of my invention reference is made to the'accompanying drawing which is a diagrammatic view of a preferred form of apparatus and circuits embodying my invention when applied to the control of a railway track switch in an interlocking system such, for example, as described in my copending application filed December 23, 1929, Serial No. 416,061, for Multiple control apparatus.

Referring to the drawing, a manually operated lever 25 when moved to the left, that is, to the position shown by the solid lines in the drawing, closes a simple circuit to a normal lever repeater relay NLP to energize that relay. Operating the lever 25 to a right-hand position, as shown by dotted lines in the drawing, closes a simple circuit for energizing a reverse lever-repeater relay RLP. With lever 25 in its left-hand position and relay NLP picked up, a normal switch controlling relay NVVR is energized by virtue of a circuit from positive terminal B of a convenient source of current such as a battery not shown, through back contact 4'! of relay RLP, front contact 6 of relay NLP, control wire 2, trailic controlled contact 48to be hereinafter referred to, control wire 2*, front contact 49 of a relay LS also to be hereinafter referred to, winding of relay NWR, and common return, wire 4 to the negative terminal C of the current source. When the lever '25 is moved to the right-hand position and relay RLP is picked up, a reverse switch controlling relay RWR is energized by virtue of a circuit from positive terminal B througha front contact 50 of relay RLP, back contact l3 of relay NLP, control Wire traffic (Cl. zit-c) controlled contact control wire 3*, front contact 52 of relay LS, winding of relay RWR and common return wire 4 to the battery terminal 0.

The traffic controlled contacts 48 and 5| may be governed in accordance with any of the customary circuit networks involving detector looking, approach locking and route. locking associated with a railway switch. These circuits form no part of my invention and are hence omitted from the drawing for the sake of clearness.

It is to be noted that with the apparatus in the position shown in the drawing, a negative cross on the control wire 2-2*= will be at once detected by causing relay NWR to become deenergized, and a positive cross on control wire 3--3 will have a shunt path to the negative terminal C of the current source through the front contact 89 of relay NLP and back contact 90 of relay RLP. If this shunt path is not complete, the relay RWR will be picked up and the presence of this positive cross on control wire 33 will thus be at once detected by the opening of a signal control circuit as will appear hereinafter. When lever 25 is reversed and relay RWR is picked up and relay NWR is down, a negative cross on control wire 3-3 will shunt relay RWR, which is now energized, and a positive cross on control wire 2-2 will be shunted to the negative terminal C through back contact 59 of relay NLP and front contact 68 of relay RLP. If this shunt path is not effective and the relay NWR shouldbe picked up, a signal control circuit to be later described would be opened and such cross detected. It follows that the double wire control circuit for the switch controlling relays NWR and RWR provides a detection of the presence of a cross on either of the control wires 2-2 or 3'-3 In accordance with usual practice a switch lock relay LS is associated with the switch controlling relays NWR. and RWR. The relay LS is normally energized because one terminal of its winding is connected to the control wire 2 which is normally connected to the positive terminal of the current source over front contact 6 of relay NLP and back contact 4'! of relay RLP, while the other terminal of its winding is connected through wire 54, back contact 55 of relay RWR and front contact 55 of relay NWR to the negative terminal C of the current source. Under the condition of lever 25 being reversed to pick up relay RLP and so to energize the reverse switch controlling relay RWR and deenergize relay NWR,this switch lock relay LS will be energized by a circuit from terminal B through back contact 51 of relay NWR, front contact 58 of relay RWR, wire 54, winding of. relay LS, wire 2, contact 48, wire 2, back contact 59 and front contact B0 to the terminal C of the current source. A resistor RA is connected across the winding of relay LS when the traffic controlled contact 48 is closed causing this relay to be somewhat slow-releasing following an operation of the lever 25 when the trafiic controlled contact 48 is closed. This will prevent relay LS from releasing immediately following an operation oflever 25, and will permit a change in energization of relays NWR and RWR to take place in response to the operation of lever 25. When the traffic controlled contact 48 is operated, resistor EA will be cut out of the circuit and relay LS will then release quickly and relay NWR or RWR, depending upon which of these relays is energized at the time, will be retained energized by a stick circuit. The stick'circuit for retaining relay NWR energized when the switch lock relay LS is deenergized as the result of the opening of the traffic controlled contact 48, can be traced from terminal B through front contact 6|, wire 63, back contact 52 of relay LS and winding of relay NWR to the terminal C. With lever 25 reversed and relay RWR energized, the stick circuit to retain relay RWR energized when the relay LS is deenergized as the result of the opening of the contact 48, extends from terminal B through its own front contact 64, wire 65, back contact 66 of relay LS and winding of relay RWR to the terminal C. A resistor RB is connected across the winding of relay NWR through the back contact I I2 of relay RWR causing relay NWR to be slowreleasing in character. A resistor RE is connected across the winding of relay RWR through the back contact I I3 of. relay NWR causing relay RWR to be slow-releasing in character. This slow-releasing characteristic of relays NWR and RWR will permit relay LS to become deenergized following an operation of contact 48 and close the stick circuit of relay NWR or RWR before these relays have released. It is clear, therefore, that as long as the traffic controlled contacts 48 and 5| are closed, the lever 25 is effective to govern the switch controlling relays NWR and RWR over circuits which include front contacts of relay LS, but that when these traffic controlled contacts are opened in response to traffic conditions in the vicinity of the track switch control of the relays NWR and RWR by the lever 25 is removed and whichever one of these relays is energized at the time is stuck energized with the result the control exerted by these relays can not be changed as long as this traffic condition exists.

The two relays NWR and RWR jointly control the normal and reverse switch operating relays NW and RW. Normally the relay NW is energized through the front contact 51 of relay NWR, back contact 68 of relay RWR and the control wire 2 as will be readily understood by an inspection of the drawing. When the lever 25 is reversed so that relay RWR is picked up and relay NWR is down, the reverse operating relay RW is energized over back contact 69 of relay NWR, front contact 10 of relay RWR and control wire 3*. It follows that the principle of requiring one control relay to be energized and. a second control relay to be deenergized in order to com plete an operating circuit is here employed in the control of the switch operating relays. NW and RW. I

The relays NW and RW in turn control the operating circuits for the switch motor M in the usual manner. These operating circuits for the motor M form no part of. my invention, and it is deemed unnecessary to describe them in detail because they will be readily understood by an inspection of the drawing.

By employing a double wire control circuit, such as heretofore described, for governing the switch controlling relays NWR and RWR, and by applying the principle of requiring one control relay to be energized and the other control relay to be deenergized before an operating circuit can be closed, a false application of power to the switch operating relays NW and RW with a subsequent false operation of the switch motor M, will not result from an accidental cross occurring in the control circuit for the switch controlling relays NWR and RWR, or on the energizing circuits of the switch operating relays NW and RW.

The switch indication relays NKR and RKR are likewise controlled by a double wire control circuit. The switch, SW when in its full normal position causes the switch circuit controller contacts I2 and 13 to occupy the positions shown by the full lines and current is then supplied from the positive terminal of a battery H through controller contact 12, control wire 2, winding of switch indication relay NKR and the common return wire 4 to the negative terminal of battery ll The winding of the reverse switch indication relay RKR. is now shunted over control wire 3, controller contact 13 and common return wire 4. Switch SW, when in its full reverse position,

causes the contacts 12 and 13 to assume the pothe current source is shunted. A negative cross I on the control wire 2 will be at once detected by theshunting of relay NKR. A positive cross on wire 3 will ordinarily result in current flowing directly back to battery H. If, however, a positive cross on wire 3 results in relay RKR being energized, the circuits controlled by the two indication relays NKR and RKR will be opened as will be explained hereinafter and such cross immediately detected. It is clear that a similar protection against a cross on wires 2 and 3 producing a false operation at a time the switch SW is reversed also obtains. These indication relays are employed to control the circuits for other relays on the principle that when one of the indication relays is energized, the other must be deenergized. To be explicit, a normal repeater relay NP is energized from battery terminal B over front contact 14 of the normal switch controlling relay NWR, back contact 15 of the reverse switch controlling relay RWR, control wire 2, front contact 16 of normal indication relay NKR, back contact 11 of reverse indication relay RKR, back contact 18 of a repeater relay RP and winding of relay NP to the negative terminal C over the common return wire 4 In the event lever 25 is reversed'so that the reverse switch controlling relay RWR is energized, switch SW is moved to its reverse position, and the reverse switch indication relay RKR is picked up, the reverse repeater relay RP is supplied with current from the battery terminal B over back contact 19 of relay NWR, front contact 80 of relay RWR, a control wire 3 back contact SI of relay NKR, front contact 82 of relay R'KR, back contact 83 of relay NP, and winding of relay RP to the negative terminal C over the return wire 4 The repeater relays NP and RF in turn control signaling circuits on the principle that when one relay is energized, the other must be deenergized, as will be clear by an inspection of the drawing. It is to be seen, therefore, that the principle of a double wire control circuit using one neutral relay for each control wire is readily adaptable to the controlling circuits associated with a railway switch, and that when so applied, false operation of the switch, or false switch indication, caused by a cross on any of the control wires, is highly improbable. Furthermore, failure of a control relay to release when deenergized will be at once detected and will not result in false operation of the devices.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claim without departing from the spirit and scope of my invention.

Having thus described my invention, What I claim is:

In combination, a railway switch having a normal and a reverse position, a manually operable lever having a normal and a reverse position, a

normal switch controlling relay and a reverse switch controlling relay, means controlled by the normal and reverse positions of the lever to energize the normal switch controlling relay and the reverse switch controlling relay respectively, means including a front contact of said normal switch controlling relay eifective to cause operation of the switch to its normal position, means including a front contact of said reverse switch controlling relay elfective to cause operation of the switch to its reverse position, an indication circuit including a normal and a reverse control wire as well as a common return wire, a current source having one terminal permanently connected to the common wire, a circuit controller operated by said switch to normal and reverse positions corresponding to the normal and reverse positions of the switch for connecting the other terminal of the current source to said normal wire or said reverse wire according to the position of the switch, a normal indication relay having its winding permanently connected between the normal and common wires, a reverse indication relay having its Winding permanently connected between the reverse and common wires; a first signaling circuit including a front contact of the normal switch controlling relay, a back contact of the reverse switch controlling relay, a front contact of the normal indication relay and a back contact of the reverse indication relay; and a second signaling circuit including a back contact of the normal switch controlling relay, a front contact of the reverse switch controlling relay, a back contact of the normal indication relay and a front contact of the reverse indication relay.

HOWARD A. THOMPSON. 

